A heterogeneous modeling method for porous media flows

This paper presents a new heterogeneous multiscale modeling method for porous media flows. Physics at the global level is governed by one set of PDEs, while features in the solution that are beyond the resolution capacity of the global model are accounted for by the next refined set of governing equations. In this method, the global or coarse model is given by the Darcy equation, while the local or refined model is given by the Darcy–Stokes equation. Concurrent domain decomposition where global and local models are applied to adjacent subdomains, as well as overlapping domain decomposition where global and local models coexist on overlapping domains, is considered. An interface operator is developed for the case where global and local models commute along the common interface. For the overlapping decomposition, a residual‐based coupling technique is developed that consistently facilitates bottom‐up embedding of scale effects from the local Darcy–Stokes model into the global Darcy model. Numerical results are presented for nonoverlapping and overlapping domain decompositions for various benchmark problems. Computed results show that the hierarchically coupled models accurately account for the heterogeneity of the medium and efficiently incorporate local features into the global response. Copyright © 2014 John Wiley & Sons, Ltd.     

Nitric Oxide Production by High Voltage Electrical Discharges for Medical Uses: A Review

Nitric oxide (NO) is a vasodilator and antihypertensive agent as well as a universal anti-microbial factor killing bacteria, fungi and parasites without killing human cells provided that an appropriate dose level and treatment time are applied. Exogenous NO is often employed in inhalation therapies for treating pulmonary hypertension in children and adults. NO generation from air in high voltage electrical discharges is being developed for medical uses because it is technologically simple, economical and portable. The related literature is reviewed here. The plasma can be a thermal plasma, where the temperature is of the order of 10,000 K, or it can be a non-thermal plasma, where the electron temperature is very high but the average gas temperature can vary over a wide range from close to room temperature to thousands of degrees above room temperature. The plasma temperature has significant effects on the chemical composition of the treated gas. These effects are explained based on the chemical reaction mechanism. Further, NO generated by electrical discharges is usually contaminated with nitrogen dioxide and sometimes with ozone and particulate matter. The techniques that have been successfully hybridized with the electrical discharge devices or that can potentially be hybridized for the purification of NO are also reviewed. Recent successful testing of electrical discharge-based NO generators for inhalation therapy on animal models in the US and routine use of them in Russia and east Europe for wound decontamination and fast heeling suggests that the technique has a great potential for applications in future.     

A set of measures to quantify the dynamicity of longitudinal social networks

This study proposes a new set of measures for longitudinal social networks (LSNs). A LSN evolves over time through the creation and/or deletion of links among a set of actors (e.g., individuals or organizations). The current literature does feature some methods, such as multiagent simulation models, for studying the dynamics of LSNs. These methods have mainly been utilized to explore evolutionary changes in LSNs from one state to another and to explain the underlying mechanisms for these changes. However, they cannot quantify different aspects of a LSN. For example, these methods are unable to quantify the level of dynamicity shown by an actor in a LSN and its contribution to the overall dynamicity shown by that LSN. This article develops a set of measures for LSNs to overcome this limitation. We illustrate the benefits of these measures by applying them to an exploration of the Enron crisis. These measures successfully identify a significant but previously unobserved change in network structures (both at individual and group levels) during Enron's crisis period. © 2015 Wiley Periodicals, Inc. Complexity 21: 309–320, 2016     

Giant micelles of organoplatinum(II) gemini amphiphiles

Organoplatinum(II) gemini amphiphiles with two different chain lengths are synthesized and characterized. Self-assembly at the air-water interface is investigated as a function of chain length and reduction in surface area by using Langmuir-trough techniques. The Langmuir-trough experiments lead to a conjecture that surface aggregates may be the adsorbing units. Atomic force microscopy on the transferred Langmuir-Schaefer films reveals spontaneous formation of wormlike micellar aggregates. A shear-induced transition and alignment are proposed for the observed effects.     

Chymotrypsin inhibitory constituents from Haloxylon recurvum

Haloxylase, the triglyceride (1), unsaturated fatty acid (2), and saturated fatty acid methyl ester (3) have been isolated from the chloroform-soluble fraction of Haloxylon recurvum. Their structures have been elucidated through spectroscopic studies and chemical transformation. All these compounds showed significant inhibitory activity against the enzyme chymotrypsin in a concentration dependent fashion.     

Influence of crystallite microstrain on surface complexes governing the metastable equilibrium solubility behavior of carbonated apatites

This study was on the influence of the mineral phase crystallite microstrain (CM) on the nature of the surface complex (SC) governing the metastable equilibrium solubility (MES) behavior of carbonated apatites (CAPs) in aqueous acidic media (0.10 M acetate buffers, with and without fluoride, 0.50 M ionic strength maintained with NaCl). The MES behavior of a set of four CAPs (synthesized at 85 degrees C by a precipitation method) of increasing CM and therefore of increasing MES (CAP4 > CAP3 > CAP2 > CAP1) was quantified. The following were the findings. For CAP1 and CAP2, the SCs deduced were Ca10(PO4)6(OH)2 and Ca10(PO4)6F2 for the nonfluoride and the fluoride cases, respectively. For CAP3 and CAP4, the SCs deduced were Ca9.5(PO4)6OH or Ca9.5(HPO4)(PO4)5(OH)2 and NaCa9.5(PO4)6F2 for the nonfluoride and the fluoride cases, respectively. These results together with that from an earlier limited study show that the Ca/P ratio of the SC decreases from 1.67 to 1.58 to 1.50 with increasing CM of the CAPs; this relationship inversely correlates with the chemistry of maturation of aqueously precipitated defective apatites. Also the SCs do not appear to exist as a continuous series and only a few SCs may account for the MES behavior over a wide range of CAP preparations.     

A dinuclear iron(II) complex, [(TPyA)FeII(THBQ(2-))FeII(TPyA)](BF4)2 [TPyA = tris(2-pyridylmethyl)amine; THBQ(2-) = 2,3,5,6-tetrahydroxy-1,4-benzoquinonate] exhibiting both spin crossover with hysteresis and ferromagnetic exchange

Dinuclear [(TPyA)FeII(THBQ(2-))FeII(TPyA)](BF4)2 (1) possesses hydrogen bonding interactions that form a 1-D chain, and pi-pi interactions between the 1-D chains that give rise to a 2-D supramolecular-layered structure, inducing hysteresis in the spin crossover behavior; 1 has shown spin crossover behavior around 250 K with thermal hysteresis and ferromagnetic interactions at low temperature.     

Mössbauer and electronic spectral characterization of homo-bimetallic Fe(III) complexes of unsymmetrical [N10] and [N12] macrocyclic ligands

The homo-bimetallic complexes of stoichiometry Fe2(L)ClO4(ClO4)2 where L are novel unsymmetrical [N10] (L1.2HClO4) and [N12] (L2.2HClO4) macrocyclic ligands, have been prepared. The ligands were obtained from an in situ capping reaction of the reactive substrate, N,N'-bis(N-ethylaniline)hydrazine-1,2-diimine with a mixture of aniline or 1,3-diaminopropane and HCHO in presence of HClO4. The compounds have been characterized by elemental analyses, conductometric, IR, FAB-mass and electronic spectral studies. IR data of complexes suggest coordination from unsymmetrical aza sites as a tridentate (N,N,N) or tetradentate (N,N,N,N) ligand. mu(eff) values of the complexes suggest presence of antiferromagnetically coupled (Fe3+-Fe3+=S5/2-S5/2) spin exchange. M?ssbauer parameters of the complexes support (+/-3/2)-->(+/-1/2) nuclear transition in high-spin configurations of Fe(III) nuclei of the homo-bimetallic complexes with the presence of Kramer's double degeneracy.     

GC–MS analysis of phytoconstituents present in Trigonella foenumgraecum L. seeds extract and its antioxidant activity

Trigonella foenumgraecum L. (TF) is a medicinal herb, belonging to the family Legumes. It has shown positive results in remedying hypo-cholesterolemic, anti-inflammatory, antibacterial, antioxidant, anti-lipidemia, antilithigenic, hepatoprotective, antiulcer, anticarcinogenic, antifungal and other miscellaneous pharmacological effects of fenugreek. The n-hexane extract of Trigonella foenumgraecum L. Seeds (TF) was analysed by gas chromatography-mass spectroscopy for identification and characterization of its therapeutic claim by traditional system. DPPH method was used to determine the antioxidant activity of Trigonella foenumgraecum L-seeds extract using UV spectrophotometer at a wavelength of 518 nm as it is one of the most sorted methods for antioxidant activity. The major compounds discovered in Trigonella foenumgraecum L. seeds extract are Linoleic acid (48.01%); 9,12-Octadecadienoic acid (Z,Z)-, 2,3-dihydroxypropyl ester (24.65%); 2-[4-Methyl-6-(2,6,6-trimethylcyclohex-1-enyl)hexa-1,3,5-trienyl]cyclohex-1-en-carboxaldehyde(1.88%); Nonane dioic acid, bis (2-ethylhexyl) ester (1.09%); Bis (2-ethylhexyl) ester of azelaic acid (11.97%); Elemicin (0.51%); cis-Linoleic acid methyl ester (0.76%); Linoleic acid chloride(0.57%); Ethyl oleate(0.18%); Isopropyl linoleate (0.38%); Dihydrovallesiachotamine (0.06%); 4-(2,2-Dimethyl-6-methylenecyclohexyl) butanal(0.12%); Citronellyl myristate (0.09%); Rhaphidecursinol B(0.25%); 5-Methoxygalbelgin (0.07%); Vitamin E (0.31%); 1,1,1,5,5,5-hexafluoro-4-{[3-(trifluoromethyl) phenyl]imino}-2-pentanone (0.76%); γ-Sitosterol (0.66%); 1-(1,5-Dimethylhexyl)-3a,12a-dimethyltetradecahydro-1H-cyclopenta[a]cyclopropa[e]phenanthren-7-ol (0.16%) and (9Z)-9-Octadecenyl (9Z)-9-hexadecenoate (1.57%). The results showed potential antioxidant activity of n-hexane extract of Trigonella foenumgraecum L. seeds by showing significant reduction in free radical against DPPH. The hexane extract of Trigonella foenumgraecum L. seeds comprises various non-water-soluble (nonpolar) constituents. These compounds were established qualitatively via GC-MS evaluation. The free radical scavenging activity of the plant extract was established owning to the presence of compounds such as terpenes, vitamin E, and unsaturated fatty acids.     

Study of K*(892)0 and φ (1020) meson production in proton-proton and Pb-Pb collisions at $\sqrt{{s}_{NN}}$=2.76 TeV

In this paper, we describe a study of charged particle yield as a function of p_T for K^*(892)⁰ and φ (1020) mesons in proton-proton (pp) and Pb-Pb collisions at $\sqrt{{s}_{NN}}$=2.76 TeV in the central rapidity region of ∣y∣<0.5, in a p_T range of 0<p_T <15 GeV c⁻¹ in pp collisions and in a p_T range of 0<p_T<20 GeV c⁻¹ in Pb-Pb collisions. We also investigated a very important ratio, the nuclear modification factor, to study the effects of the medium in the most central region, i.e. 0%-5% centrality. For data simulation, we used the EPOS-LHC and EPOS-1.99 models. To check the validity of these models’ simulations, we compared the data obtained from these Monte Carlo simulation programs with ALICE experimental data for $\sqrt{{s}_{NN}}$=2.76 TeV. It was concluded that the models’ predictions for the φ-meson in pp and for the most central Pb-Pb collisions disagreed with the ALICE data, and that the difference increased with p_T. This may be connected with the essential role of collective parton behaviors which could not have been taken into account by the models. For K^*0 mesons, both programs gave almost the same predictions, and with p_T in the interval p_T>3 GeV c⁻¹, the predictions were very close to the experimental data. Both models gave higher predictions for the soft p_T interval and lower predictions for the hard interactions. The values of the R_AA distributions were lower than unity and both models were very close to the ALICE data. It is very interesting that the models were not able to describe the p_T distributions, but they gave good predictions for their ratios. This may possibly be due to parton collective behaviors. We observed some additional suppression of K^*0 at low values of p_T with respect to φ-mesons, which may be related to the role of the masses of the particles in soft interactions. The rising trend for R_AA in the region from p_T =10 GeV c⁻¹ to 20 GeV c⁻¹ observed by the ALICE experiment was absent for the φ-mesons.